This invention relates generally to devices for measuring body temperature and in particular to devices and apparatus for measuring tracheal temperatures during operations.
During operations in which a patient is under anesthesia, a medical condition known as malignant hyperthermia may occur resulting in death of the patient. The symptoms for such a condition include a sudden rise in body temperature of the patient followed shortly thereafter by death. Where such sudden body temperature rises can be detected in time, clinical procedures can be implemented which would save the life of the patient. Devices of the prior art for measuring body temperature have used temperature sensing devices such as thermisters or thermocouples placed in the rectum, esophagus or tympanic membrane, however, they are difficult to use routinely. Devices for measuring body temperatures in the trachea have not been used in the past because they get in the way of the endotracheal tube used to administer anesthesia and their temperature readings are affected by the incoming air temperature, unless a rebreather system is used, which prevents an accurate, constant reading of body temperature. To continuously monitor body temperature within the trachea, such measurements, in order to provide meaningful information, must either not be affected by any cool incoming air entering the trachea or must have a time constant sufficient to measure the temperature of the air exhaled by the patient in order to relate the air temperature to body temperature.